1. Field of the Invention
The present invention relates to an image processing apparatus that processes an input image signal to generate a print signal and, more particularly, to such apparatus equipped with an automatic color saturation controller.
2. Description of the Prior Art
Technical development relative to a still print image processing system is currently in progress, wherein a video signal (still image signal) of one frame obtained from a video source such as a television camera, video disk, electronic still camera or the like is supplied to an image processor, which then processes the input image signal to generate a desired print signal. The print signal is supplied to a printing device to control the printing of the image.
FIG. 9 is a block diagram of an exemplary image processing system, wherein reference numeral 1 denotes an image signal output unit for generating a video signal (still image) of one frame. The image signal output unit may comprise or respond to a television camera or the like. The still image signal derived therefrom is fed to an image processor 2 and then is processed in compliance with the signals generated by a processing control console 2A. The image processing executed with respect to the supplied original still image signal includes noise reduction, luminance control, color saturation control, image conversion (enlargement, reduction, rotation, image size change) and so forth. Such image processing is conventional per se and thus not described in detail herein. The processing control console 2A comprises input means such as a keyboard and a mouse and display means including a processing operation monitor, an image monitor and so forth.
A printer 3 is supplied with the output signal of the image processor 2 suitably converted to print signals of, e.g., four colors C, M, Y and K (cyan, magenta, yellow and black) after completion of the various image processings, whereby the operation of printing the color image is executed by the printer 3.
In the image processing system mentioned, there exists the problem that when the image signal obtained from a video camera or the like is fed into the image processor 2 via the image signal output unit 1 and then the image is processed by the image processor 2 while being displayed on a monitor television receiver or the like, the color saturation of the printed image is reduced as compared to the color saturation of the image displayed on the monitor television receiver.
If a proper color saturation is not obtained, the color saturation can be improved by individually controlling the three primary color signals R, G, B (red, green, blue) or C, M, Y (cyan, magenta, yellow) in the printer 3. In such a case, however, the color phase is changed simultaneously so that there is considerable difficulty, when employing individual color adjustment, in controlling the color saturation without disturbing the color phase.